1. Field of the Invention
The present invention relates to an ink-jet head for ejecting ink from an ink ejection port.
2. Description of Related Art
An ink-jet head for ejecting ink from an ink ejection port includes a passage unit, a reservoir unit and an actuator unit. The passage unit has an ink ejection port and a pressure chamber communicating with the ink ejection port. The reservoir unit supplies ink to the passage unit. The actuator unit supplies a pressure to ink in the pressure chamber.
In such ink-jet head as disclosed in Japanese Unexamined Patent Publication No. 2005-59438, the reservoir unit is disposed on the passage unit. On the lower surface of the reservoir unit, the ink discharging ports protrude downward, and the reservoir unit and the passage unit are in contact with each other only at regions surrounding openings of the lower surface of the ink discharging ports. Between the passage unit and the reservoir unit, a gap is formed except areas where the passage unit and reservoir unit are in contact each other. The actuator units are disposed in the gap. Both ends in lateral direction of the reservoir unit are respectively provided with two draw-out grooves recessed inward in lateral direction. A flexible printed circuit (FPC) connected to the upper surface of the actuator unit is draw-out upward through the draw-out groove. In addition, the side face of the reservoir unit is covered with a lower cover. The lower cover is a plate substantially rectangular in shape, under which a convex part is formed that corresponds to the draw-out groove. The lower cover is disposed such that its convex part covers the FPC in the draw-out groove from outside. In the meantime, the lower end of the lower cover other than the convex part and the upper surface of the reservoir unit are brought into close contact with each other. It is therefore prevented ink from being introduced into the ink-jet head. The convex part is formed so as to define a gap between the upper surface of the passage unit, so that the lower end of the convex part does not contact the upper surface. Thus, even though the length of the convex part is slightly raised due to a manufacturing tolerance, the convex part does not contact the upper surface of the passage unit. As a result, it is not prevented the lower end of the lower cover other than the convex part and the upper surface of the reservoir unit from being brought into contact with each other. In addition, configuring the ink-jet head as above, the lower cover is within a width of a head main body in a sub scanning direction (lateral direction) so that the ink-jet head is made smaller.